1. Field of the Invention
The present invention relates to a method for simulating the electrical characteristics of an electronic device and an apparatus for generating input data for the simulation of the electrical characteristics of an electronic device. For example, the present invention can be used as a technique to generate input data for various simulators and a tool for generating such data wherein information required for data to be used in the simulation of the capacity and current density of a line in a semiconductor device and the like is easily created on a computer with the aid of three dimensional shape input.
2. Description of the Related Art
The so-called 3D-CAD""s (three-dimensional computer aided designers) including IDEAS (the trademark of a CAD from Structural Dynamic Res. Corp.) are known as data input apparatuses for three-dimensional simulation. Such general purpose three-dimensional input apparatuses have the following problems when used for the simulation of the capacity and current density of a line in a semiconductor device.
(1) Although various shapes can be input and complicated shapes can be specified, this requires an operator to master many operations. In the field of semiconductor devices wherein only a few kinds of simple shapes need to be input, such a technique unnecessarily increases complicatedness in operation.
(2) With such a technique, it is difficult to specify only a particular attribute of a shape, e.g., the specific resistance of a certain solid and whether a certain plane is an electrode or not.
(3) It is difficult to specify the relationship between shapes, e.g., whether they are continuous and whether they are parts of the same electrode.
On the other hand, simulation tools for electrical devices which are available on the market are conversely limited in the kinds of shapes that can be input using them (they can only input rectangular solids or the like). This is not sufficient to satisfy the actual needs in the art.
In consideration to such problems, there is a need for a system which allows the input of only particular shapes that are required for the simulation of a semiconductor device to simplify input operations and with which only required attributes can be reliably and simply set. However, no technique has been developed to achieve such a goal.
It is an object of the present invention to provide a technique suitable for the simulation of a semiconductor device. More specifically, it is an object of the present invention to provide a method for simulating the electrical characteristics of a semiconductor device and an input data generation apparatus for the simulation of the electrical characteristics of a semiconductor device which allow, for example, the simulation of the capacitance an d current density of a line in a semiconductor device to be carried out in such a manner that required data can be easily obtained, for example, on a screen and can be reused as input data for various simulators; data can be accurately generated; and the time for such operations can be shortened.
According to the present invention, the above-described object is achieved by a method for simulating the electrical characteristics of an electronic device, e.g., semiconductor device which includes a step of specifying the material, electrical characteristics and shape of a part of interest of a semiconductor device, the specification of the shape being performed by selecting it from among several preselected simplified shape models.
According to another aspect of the invention, the above-described object is achieved by a method for simulating the electrical characteristics of a semiconductor device wherein a shape is specified by selecting it from among a truncated-conical shape, a hexahedral shape, and a spoon-cut shape.
According to another aspect of the invention, the above-described object is achieved by a method for simulating the electrical characteristics of a semiconductor device wherein a hexahedral shape is specified by selecting it from among rectangular solids and a shape connecting rectangular solids.
According to another aspect of the invention, the above-described object is achieved by a method for simulating the electrical characteristics of a semiconductor device wherein the electrical characteristics to be simulated are the electrical characteristics of a line in a semiconductor device and wherein steps are provided for inputting data indicating the material of the line to be simulated, data indicating the resistance of the line, data specifying the positions of electrodes in the line, data specifying the shape of the line, and data indicating the relationship between lines.
According to another aspect of the invention, the above-described object is achieved by an apparatus for generating input data for simulation which generates input information required for the simulation of the electrical characteristics of an electronic device, e.g., a semiconductor device wherein the material, electrical characteristics and shape of a part of interest of a semiconductor device is specified, the specification of the shape being performed by selecting it from among several preselected simplified shape models.
According to another aspect of the invention, the above-described object is achieved by an apparatus for generating input data for the simulation of the electrical characteristics of a semiconductor device wherein a shape is specified by selecting it from among a truncated-conical shape, a hexahedral shape, and a spoon-cut shape.
According to another aspect of the invention, the above-described object is achieved by an apparatus for generating input data for the simulation of the electrical characteristics of a semiconductor device wherein a hexahedral shape is specified by selecting it from among rectangular solids and a shape connecting rectangular solids.
According to another aspect of the invention, the above-described object is achieved by an apparatus for generating input data for the simulation of the electrical characteristics of a semiconductor device wherein the electrical characteristics to be simulated are the electrical characteristics of a line in a semiconductor device and wherein steps are provided for inputting data indicating the material of the line to be simulated, data indicating the resistance of the line, data specifying the positions of electrodes in the line, data specifying the shape of the line, and data indicating the relationship between lines.
In the context of the present invention, the term xe2x80x9cmaterialxe2x80x9d refers to data indicating the substance(s) that constitutes an object, and the term xe2x80x9celectrical characteristicsxe2x80x9d refers to data or the like indicating the resistance of the material (dielectric constant or specific resistance). According to the present invention, the material and electrical characteristics of a part of interest are set. In this case, the material and the dielectric constant (specific resistance) and the like which are the electrical characteristics thereof can be written in a database in advance, and a user can use such values or can arbitrarily set such values.
According to the present invention, a shape is specified by selecting it from among several preselected simplified shape models which are typically a truncated-conical shape, a hexahedral shape, and a spoon-cut shape. In the implementation of the present invention, three kinds of shapes, i.e., xe2x80x9chexahedral shapexe2x80x9d, xe2x80x9ctruncated-conical shape (including cylindrical shape)xe2x80x9d, and xe2x80x9cspoon-cut shapexe2x80x9d, can be typically set as shapes that can be handled. Further, two kinds of hexahedral shapes, i.e., rectangular solids and a shape connecting rectangular solids, can be set.
It is possible to specify that an object is an electrode as an electrical characteristic (electrical attribute) especially when the object is specified as a hexahedron. In general, an electrode is an attribute of a face of a solid. An electrode may extend across a plurality of faces or a plurality of solids. Therefore, one face of a hexahedron may be specified as an xe2x80x9celectrodexe2x80x9d. Alternatively, two or more faces of a hexahedron may be specified as an xe2x80x9celectrodexe2x80x9d. Further, the present invention allows a configuration wherein two attributes, i.e., electrodes and connection can be easily defined as electrical characteristics. For example, electrodes can be specified in an item named xe2x80x9celectrode No.xe2x80x9d.
The definition of a hexahedron that connects rectangular solids can be easily given by specifying the names of the two rectangular solids to be connected. In general, such definition of a hexahedron connecting straight lines is sufficient in an application limited to a line in a semiconductor device.
There is a method of defining overlapping relationships between shapes called CSG (constructive solid geometry) wherein an overall shape is defined by combining particular shapes. In general, CSG involves various operations on shapes (e.g., addition, subtraction, and multiplication) which are executed in combining (overlapping) primitives (basic shapes) prepared in advance. According to the present invention, however, the order in which shapes are input plays an important role and such definition can be given in accordance with only one rule that a figure is replaced by the next figure defined. In general, this rule solely suffices the requirements in the field of semiconductor devices, and this simplifies operations.
The format for storing shapes is represented in the form of a text file consisting of parameters that characterize shapes. Although shapes are normally processed on a shape input module, they may be directly created or edited by a text editor.
In the implementation of the present invention, a mesh generation module may be used to generate a mesh that depends on the shape which has been generated. Various tools available on the market may be used as a mesh generation module for such a purpose.
A simulation data generation module is a module for generating input data for a particular simulator based on shape data, attribute data, and the result of meshing.